Method of absorbing oxids of nitrogen.



UNITED STATES PATENT OFFICE.

BIRGER FJELD HALVORSEN, OF CHRISTIANIA, NORWAY, ASSIGNOR TO NORSK HYDRO-ELEKTRISK KVAELSTOFAKTIESELSKAB, OF CHRISTIANIA, NORWAY.

METHOD OF ABSORBING OXIDS OF NITROGEN.

Specification of Letters Patent.

Patented Jan. 26, I909.

Application filed March I9, 1908. Serial No. 4=22,129.

To all whom it may concern:

Be it known that I, BIRGER FJELD HAL- VORSEN, a subject of the King ofNorway, residing at Christiania, Norway, have invented certain new anduseful Improvements in Methods of Absorbing Oxids of Nitrogen; and I dohereby declare the following to be a a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same. p

My invention relates to the utilization of nitrous gases and consists ina method of absorbing nitrous gases substantially for the purpose ofproducing nitric acid and pure nitrites. It is a Well known fact that intreating nitrous gases, such as are, for instance, obtained by thecombustion of atmospheric nitrogen by means of an electric arc, withalkaline absorbing agents, a mixture of nitrate and nitrite isvgenerally obtained. Such mixed products cannot be directly utilized inthe arts, and attempts have therefore been made to avoid said drawbackby the use-of special measures. I

According to the present invention the result aimed at is attained byutilizing the gases in such a manner that they are first treated withwater to obtain nitric acid, according to the following reactions:

and that the highly diluted remaininggases are thereupon caused to beabsorbed in caustic alkalies or carbonates of alkali; or

in caustic alkalies and carbonates of alkali;

for it appears that such diluted gases principally or exclusivelycontain nitrogen in the oWer stages of oxidation, and when absorbed bythe said absorbing agents give pure nitrites. The reaction with causticsoda may be expressed as follows- .NO No anon 2NaNO H 0,

and with a carbonate of the alkalies, as sodium carbonate, the reactionmay be expressed as follows NO+NO +Na CO =2NaNO 00,.

In this manner pure nitric acid is obtained from the nitrous gases inthe first part of the absorbing process, thereof substantially purenitrites are obtained.

I claim? 1. The method of absorbing nitrous gases, comprising firsttreating the gas with Water and conducting the gases resulting therefrom into an alkaline absorbent.

2. The method of absorbing nitrous gases, comprising first treatin saidases with water and conducting t e resu ting ases into an absorbentcontaining caustic a kali.

3. The method of absorbing nitrous gases, comprisin first treating saidgases with Water an conducting the resulting gases into an absorbentcontaining caustic alkali and a carbonate of the alkalies.

In testimony that I claim the foregoing as my invention, Ihave signed myname in presence of two subscribing witnesses.

BIRGER FJELD HALVORSEN.

Witnesses:

HENRY Bonnnwron,

MICHAEL ALGER.

andi in the last part

